Five Egyptian police officers are not being prosecuted in connection with the 2016 murder of Italian student Giulio Regeni. The Egyptian prosecutor on Wednesday asked investigators to remove agents from the investigation.

The prosecution said it would not prosecute the five officers because it is unknown who is behind the murder. According to the prosecutor, the investigation into the murder will continue.

Italian prosecutors alluded to four Egyptian agents for the torture and death of Regeni earlier this month.

Regeni’s death sparked considerable outrage in Italy, putting considerable pressure on diplomatic relations with Egypt. The Italian government accused Egyptian officials of not cooperating in the investigation into the student’s death.

Prosecutors said Regeni’s parents took his son’s laptop with him shortly after his death before being inspected by authorities. Italy is said to have rejected requests to transfer laptops.

The student was tortured and murdered

Regeni, a 28-year-old graduate student from Cambridge University, researched the rise of independent trade unions in Egypt. He disappeared without a trace in late January 2016. His body was found in the ditch two weeks later and he showed traces of torture.

Critics of Egyptian rule accused the security forces of being involved. The Egyptian government denied this. Autopsy first revealed that the victim must have been tortured for a week before killing him.

Trade unions are a sensitive subject in Egypt. Under a pseudonym, the student wrote several articles criticizing the Egyptian rule.